Multi-phase buck-boost charger architecture

Abstract

A multi-phase buck-boost converter system can include an external discrete component power stage and a controller integrated circuit. The external discrete component power stage can include a first and second phases each respectively having an input half bridge including first and second or third and fourth discrete switching devices and corresponding first and second discrete inductors operable as first and second buck stages. The controller integrated circuit can include a first and second output half bridges respectively corresponding to the first and phases and respectively having fifth and sixth or seventh and eighth integrated switching devices respectively coupled to the first or second discrete inductors and respectively operable as first and second boost stages in conjunction with the first and second buck stages as a first buck-boost converter and controller circuitry that operates the first and second buck-boost converters to produce a regulated output voltage from an input voltage.

1 . A multi-phase buck-boost converter system comprising an external discrete component power stage and a controller integrated circuit, wherein:
 the external discrete component power stage includes:
 a first phase having an input half bridge including first and second discrete switching devices and a corresponding first discrete inductor operable as a first buck stage; and 
 a second phase having an input half bridge including third and fourth discrete switching devices and a corresponding second discrete inductor operable as a second buck stage; and 
   the controller integrated circuit includes:
 a first output half bridge corresponding to the first phase and having fifth and sixth integrated switching devices coupled to the first discrete inductor and operable as a first boost stage in conjunction with the first buck stage as a first buck-boost converter; 
 a second output half bridge corresponding to the second phase and having seventh and eighth integrated switching devices coupled to the second discrete inductor and operable as a second boost stage in conjunction with the second buck stage as a second buck-boost converter; and 
 controller circuitry that operates the first and second buck-boost converters to produce a regulated output voltage from an input voltage. 
   
     
     
         2 . The multi-phase buck-boost converter system of  claim 1  wherein the first and second phases and first and second output half bridges are operable for high load operation, and only one of the first phase and first output half bridge or second phase and second output half bridge is operable for low load operation. 
     
     
         3 . The multi-phase buck-boost converter system of  claim 1  wherein:
 the regulated output voltage is used for battery charging; and 
 the controller integrated circuit further comprises controller circuitry that controls a charging voltage delivered to a battery. 
 
     
     
         4 . The multi-phase buck-boost converter system of  claim 3  wherein the controller integrated circuit includes one or more sensing inputs selected from the group consisting of: an input voltage sensing input, an input current sensing input, an output voltage sensing input, and a battery current sensing input. 
     
     
         5 . The multi-phase buck-boost converter system of  claim 1  wherein the fifth, sixth, seventh, and eighth switching devices are integrated on a single integrated circuit die with the controller circuitry that operates the first and second buck-boost converters to produce the regulated output voltage from the input voltage. 
     
     
         6 . The multi-phase buck-boost converter system of  claim 1  wherein the first, second, third, and fourth discrete switching devices are GaN switching devices. 
     
     
         7 . The multi-phase buck-boost converter system of  claim 1  wherein the controller circuitry that operates the first and second buck-boost converters to produce the regulated output voltage from the input voltage operates the first and second buck-boost converters at the same switching frequency and 180 degrees out of phase. 
     
     
         8 . The multi-phase buck-boost converter system of  claim 1  wherein the first, second, third, fourth, fifth, sixth, seventh, and eighth switching devices are MOSFET devices. 
     
     
         9 . A controller integrated circuit for a multi-phase buck-boost converter system, the controller integrated circuit comprising:
 a first output half bridge corresponding to a first phase of the multi-phase buck-boost converter system and having first and second integrated switching devices couplable to a first external inductor and operable as a first boost stage in conjunction with a first external discrete component buck stage as a first buck-boost converter;   a second output half bridge corresponding to a second phase of the multi-phase buck-boost converter system and having third and fourth integrated switching devices couplable to a second external inductor and operable as a second boost stage in conjunction with a second external discrete component buck stage as a second buck-boost converter; and   controller circuitry that operates the first and second buck-boost converters to produce a regulated output voltage from an input voltage.   
     
     
         10 . The controller integrated circuit for a multi-phase buck-boost converter system of  claim 9  wherein the first and second phases and first and second output half bridges are operable for high load operation, and only one of the first phase and first output half bridge or second phase and second output half bridge is operable for low load operation. 
     
     
         11 . The controller integrated circuit for a multi-phase buck-boost converter system of  claim 9  wherein:
 the regulated output voltage is used for battery charging; and 
 the controller integrated circuit further comprises controller circuitry that controls a charging voltage delivered to a battery. 
 
     
     
         12 . The controller integrated circuit for a multi-phase buck-boost converter system of  claim 11  wherein the controller integrated circuit includes one or more sensing inputs selected from the group consisting of: an input voltage sensing input, an input current sensing input, an output voltage sensing input, and a battery current sensing input. 
     
     
         13 . The controller integrated circuit for a multi-phase buck-boost converter system of  claim 9  wherein the first, second, third, and fourth switching devices are integrated on a single integrated circuit die with the controller circuitry that operates the first and second buck-boost converters to produce the regulated output voltage from the input voltage. 
     
     
         14 . The controller integrated circuit for a multi-phase buck-boost converter system of  claim 9  wherein the controller integrated circuit includes a plurality of drive outputs each corresponding to an external discrete switching device of the first or second external buck stages. 
     
     
         15 . The controller integrated circuit for a multi-phase buck-boost converter system of  claim 9  wherein the controller integrated circuit includes a first and second power inputs respectively couplable to the first and second external inductors that connect the first and second external inductors to respective switch nodes of the first and second output half bridges. 
     
     
         16 . The controller integrated circuit for a multi-phase buck-boost converter system of  claim 9  wherein the controller circuitry that operates the first and second buck-boost converters to produce the regulated output voltage from the input voltage operates the first and second buck-boost converters at the same switching frequency and 180 degrees out of phase. 
     
     
         17 . An electronic device comprising:
 one or more electronic systems selected from the group consisting of a processor, a memory, storage, a display, an input device, an I/O interface, and a network interface; and   a power system including a multi-phase buck-boost converter system that includes an external discrete component power stage and a controller integrated circuit, wherein:
 the external discrete component power stage includes:
 a first phase having an input half bridge including first and second discrete switching devices and a corresponding inductor operable as a first buck stage; and 
 a second phase having an input half bridge including third and fourth discrete switching devices and a corresponding inductor operable as a second buck stage; and 
 
 the controller integrated circuit includes:
 a first output half bridge corresponding to the first phase and having fifth and sixth integrated switching devices coupled to the first inductor and operable as a first boost stage in conjunction with the first buck stage as a first buck-boost converter; 
 a second output half bridge corresponding to the second phase and having seventh and eighth integrated switching devices coupled to the second inductor and operable as a second boost stage in conjunction with the second buck stage as a second buck-boost converter; and 
 
 controller circuitry that operates the first and second buck-boost converters to produce a regulated output voltage from an input voltage, wherein the regulated output voltage is used to power the one or more electronic systems. 
   
     
     
         18 . The electronic device of  claim 17  wherein the first and second phases and first and second output half bridges are operable for high load operation, and only one of the first phase and first output half bridge or second phase and second output half bridge is operable for low load operation. 
     
     
         19 . The electronic device of  claim 17  wherein:
 the power system includes a battery; 
 the regulated output voltage is used for battery charging; and 
 the controller integrated circuit further comprises controller circuitry that controls a charging voltage delivered to a battery. 
 
     
     
         20 . The electronic device of  claim 17  wherein the fifth, sixth, seventh, and eighth switching devices are integrated on a single integrated circuit die with the controller circuitry that operates the first and second buck-boost converters to produce the regulated output voltage from the input voltage. 
     
     
         21 . The electronic device of  claim 17  wherein the first, second, third, and fourth discrete switching devices are GaN switching devices. 
     
     
         22 . The electronic device of  claim 17  wherein the controller circuitry that operates the first and second buck-boost converters to produce the regulated output voltage from the input voltage operates the first and second buck-boost converters at the same switching frequency and 180 degrees out of phase. 
     
     
         23 . The electronic device of  claim 17  wherein the first, second, third, fourth, fifth, sixth, seventh, and eighth switching devices are MOSFET devices.